Summary Gammy ray and x-ray irradiation of cellular blood components to prevent the development of transfusion-associated graft versus host disease (TA-GVHD) is an FDA approved process. However, in the United States substantial and onerous security requirements for use of radioactive isotopes for gamma ray irradiators has resulted in a rapid shift toward x-ray irradiators to prevent TA-GVHD at low dose. Higher dose irradiation is a potential means to address the additional concern nowadays associated with blood products contaminated with new and emerging transmitted infectious diseases but the irradiation times would be too long and costly using conventional x-ray irradiators. Alternate pathogen reduction technologies such as INTERCEP and Mirasol require ultraviolet irradiation which has limited penetration depth to treat packaged blood products. The proposed research will create high flux rate x-ray panels capable of delivering doses within seconds to prevent TA-GVHD plus destroy pathogens. The enabling technology is generation of a discharge in a gas as a novel robust stable source of electrons which are accelerated to a panel to produce x-rays of the desired energy. Uniform discharges have been demonstrated over an electrode area large enough that if separated into two 15cm by 15 cm panels they could be utilized for front and backside irradiation. Discharge currents of more than 10 A/cm2 have been demonstration. Electrons extracted from the plasma have been accelerated to a collector at distances up to 15cm in a triode structure. At the collector the delivered charge was more than 10x that of the most advanced photocathodes. The Phase I research will focus on a demonstration that the extracted electrons can be accelerated to the potential of a conventional x-ray tube producing x-rays with energies sufficient to penetrate through the thickness of packaged blood and that uniform extraction occurs over large electrode areas. To demonstrate proof-of-concept, a small- scale assessment of the impact of high-flux irradiation on cellular blood products will be performed. Results of Phase I will set the stage for an in-depth study of the effects of high fluence and high dose irradiation of blood products in Phase II.